ESO has called on the expertise of Kirkholm A/S, a Danish engineering consultancy company, for the task of solving two significant challenges with direct impact on the E-ELT’s design.

The European Extremely Large Telescope (E-ELT) project is motivated by a wide range of scientific challenges being encountered by modern astronomy, and, likewise, its design presents many engineering challenges that border on determining what is even technically possible. ESO, which is behind this ambitious project, is drawing on some of the world’s best engineering experts in order to realize its goals.

One key challenge is to maintain high accuracy in such a large telescope despite changing external factors. The E-ELT’s optics will rely on a primary mirror measuring an astonishing 39 meters in diameter. Temperature differences between the upper side and lower side of the gigantic mirror can deform the mirror segment and, thereby, ruin or distort the telescope’s accuracy.

Kirkholm’s analysis paves the way to a solution

ESO needed a way to allow for corrections of such temperature factors in real-time, and to get there, they needed a highly reliable and detailed analysis of the thermal conditions around both surfaces of the mirror. ESO engaged the Danish consultant firm Kirkholm Mechanical Engineering for the task.

Kirkholm engineers carried out their calculations using CFD (Computational Fluid Dynamics) software, and provided detailed analyses of how the mirror is heated over time. Kirkholm’s results now allow ESO to design automatic systems for controlling the temperatures inside the dome that contains the telescope – thereby ensuring consistent optical accuracy.

ESO asks for more of Kirkholm’s high quality services

After proving themselves through the analysis project, Kirkholm’s consultants were soon called on once again by ESO who sought help with an entirely different task in connection with the E-ELT project. Kirkholm was contracted to draw up requirement-specifications and two potential concepts for the development of E-ELT’s Pre-Focal Station (PFS).

The PFS has two main functions, one of which is to receive light from the telescope and relay it to the scientific instruments. Additionally, the PFS houses the devices that control the telescope’s advanced adaptive optics and its direction towards the sky. The Pre-Focal Station is a key component in the overall E-ELT telescope construction, and ESO wanted Kirkholm’s expert input on the design aspects of the PFS before the actual development project was put out to tender.